Our actions can sometime be a reflection of how we are actually feeling inside. While we might think that we can control our emotions, hide them away so that others would not find out or worse, be a punching bag to satisfy those negative ones, the truth is that we cannot really control them all the time. Same goes for other people. It is admittedly hard to have compassion when you are on the receiving end, but that is sometimes just the reality. Hurt people hurt. So do not take it too personally or write that person off totally. If you do not see yourself being in that situation anymore, you are free to leave that environment. In the meantime, do a check on yourself and see how are you really doing inside? Be honest with yourself. If you need to seek help or do something about it, go ahead and do it. When you are good with yourself, you are inherently doing good to others as well.